Pytohn实现Linux shell中的wc命令
#!/usr/bin/pythonimport sys
import os
from optparse import OptionParser
def opt():
parser = OptionParser()
parser.add_option("-c", "--char",
dest="chars",
action="store_true",
default=False,
help="only count chars")
parser.add_option("-w", "--work",
dest="words",
action="store_true",
default=False,
help="only count words")
parser.add_option("-l", "--line",
dest="lines",
action="store_true",
default=False,
help="only count lines")
parser.add_option("-n", "--no-total",
dest="total",
action="store_true",
default=False,
help="only count total")
options, args = parser.parse_args()
return options, args
def get_count(data):
chars = len(data)
words = len(data.split())
lines = data.count('\n')
return lines, words, chars
def print_wc(options, lines, words, chars, fn):
if options.lines:
print lines,
if options.words:
print words,
if options.chars:
print chars,
print fn
def main():
options, args = opt()
if not (options.lines or options.words or options.chars):
options.lines, options.words, options.chars = True, True, True
if args:
file = 0
total_lines, total_words, total_chars = 0, 0, 0
for fn in args:
if os.path.isfile(fn):
with open(fn) as fd:
data = fd.read()
lines, words, chars = get_count(data)
print_wc(options, lines, words, chars, fn)
total_lines += lines
total_words += words
total_chars += chars
file += 1
elif os.path.isdir(fn):
print >> sys.stderr, "%s: is a directory" % fn
else:
sys.stderr.write("%s: No such file or direcotry\n" % fn)
if file > 1 andnot options.total:
print_wc(options, total_lines, total_words, total_chars, "total")
else:
data = sys.stdin.read()
fn = ''
lines, words, chars = get_count(data)
print_wc(options, lines, words, chars, fn)
if __name__ == '__main__':
main()
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